Membrane fluidized bed

The added-particle effect is also evident in the application of fluidized beds to provide turbulence promotion. Figure 10.46 is a schematic diagram of a combined tubular membrane-fluidized bed system. It consists of a tubular membrane module, fluidized particles, a feed pump, and the feed storage tank. During the operation, the particles are fluidized... 

However, besides the high heat exchange coefficients, fluidized beds are also suitable for isothermal operations even if a highly exothermic reaction is occurring. This has been demonstrated a.o. by Deshmukh et al. [46,47], who carried out oxidative dehydrogenation of methanol in laboratory-scale membrane fluidized bed reactors. The authors found virtually isothermal conditions even for very high methanol feed concentrations. This important... 

Indeed, Roy et aL first demonstrated that autothermal operation could be achieved by directly adding oxygen to a fluidized bed reformer to provide all of the heat required via the partial oxidation reaction [24], The extension of this work to a membrane fluidized bed reactor has been performed by the same... 

Figure 7.6 Schematic of bi-membrane fluidized bed reactor for pure H2 and pure CO2 production. Reproduced from [12], With permission from Elsevier.

Membrane reactors are defined here based on their membrane function and catalytic activity in a structured way, predominantly following Sanchez and Tsotsis [2]. The acronym used to define the type of membrane reactor applied at the reactor level can be set up as shown in Figure 10.4. The membrane reactor is abbreviated as MR and is placed at the end of the acronym. Because the word membrane suggests that it is permselective, an N is included in the acronym in case it is nonpermselective. When the membrane is inherently catalytically active, or a thin catalytic film is deposited on top of the membrane, a C (catalytic) is included. When catalytic activity is present besides the membrane, additional letters can be included to indicate the appearance of the catalyst, for example, packed bed (PB) or fluidized bed (FB). In the case of an inert and nonpermselective... 

General Characteristics. Energy addition or extraction from fast fluidized beds are commonly accomplished through vertical heat transfer surfaces in the form of membrane walls or submerged vertical tubes. Horizontal tubes or tube bundles are almost never used due to concern with... 

Mahalingan, M., and Kolar, A. K., Heat Transfer Model for Membrane Wall of a High Temperature Circulating Fluidized Bed, Circ. Fluid. Bed Tech. Ill, 239-246 (1990)... 

An integrated proof-of-concept (POC) size fluidized-bed methane reformer with embedded palladium membrane modules for simultaneous hydrogen separation is being developed for demonstration (Tamhankar et al., 2007). The membrane modules will use two 6 in. X 11 in. Pd-alloy membrane foils, 25-pm thick, supported on a porous support. The developmental fluidized-bed reactor will house a total of five (5) membrane modules with a total membrane area of about 0.43 m2 and is scheduled for demonstration by September 2007. 

Support coated open tubular (SCOT) columns, 4 615 6 379 Supported liquid membranes, 16 28 Support material, in fluidized-bed encapsulation, 11 540 affinity chromatography, 6 392-393 chromatography, 6 375 gas chromatography, 6 375 Supported metals... 

Industrial hazardous wastewater can be treated aerobically in suspended biomass stirred-tank bioreactors, plug-flow bioreactors, rotating-disc contactors, packed-bed fixed-biofilm reactors (or biofilters), fluidized bed reactors, diffused aeration tanks, airlift bioreactors, jet bioreactors, membrane bioreactors, and upflow bed reactors [28,30]. 

The drier also includes instruments for measuring the temperature of material in a fluidized bed, the temperatures of incmoming and outgoing air in respective sections, a differential pressure. Also provided are inspection and cleaning holes and burst-proof membranes. 

Once an undesirable material is created, the most widely used approach to exhaust emission control is the application of add-on control devices (6). For organic vapors, these devices can be one of two types, combustion or capture. Applicable combustion devices include thermal incinerators (qv), ie, rotary kilns, liquid injection combusters, fixed hearths, and fluidized-bed combustors catalytic oxidization devices flares or boilers/process heaters. Primary applicable capture devices include condensers, adsorbers, and absorbers, although such techniques as precipitation and membrane filtration are finding increased application. A comparison of the primary control alternatives is shown in Table 1 (see also Absorption Adsorption Membrane technology). 

Experiments were conducted at the University of Magdeburg to examine the partial oxidation of ethane to ethylene by dosing oxygen into the fluidized bed of porous catalysts using immersed sintered metal and ceramic membranes. These studies were related to a DFG (German Research Association) research group (DFG-Nr. FOR 447/1-1) Membrane supported reaction engineering in the subproject Fluidized-bed membrane reactor . 

Until now, bioreactors of various types have been developed. These include loop-fluidized bed [14], spin filter, continuously stirred turbine, hollow fiber, stirred tank, airlift, rotating drum, and photo bioreactors [1]. Bioreactor modifications include the substitution of a marine impeller in place of a flat-bladed turbine, and the use of a single, large, flat paddle or blade, and a newly designed membrane stirrer for bubble-free aeration [13, 15-18]. Kim et al. [19] developed a hybrid reactor with a cell-lift impeller and a sintered stainless steel sparger for Thalictrum rugosum cell cultures, and cell densities of up to 31 g L1 were obtained by perfusion without any problems with mixing or loss of cell viability the specific berberine productivity was comparable to that in shake flasks. Su and Humphrey [20] conducted a perfusion cultivation in a stirred tank bio-... 

Adds, A. Lim, C. Grace, J. The Fluidized Bed Membrane Reactor System A Pilot-Scale Experimental Study Chemical Engineering Science 49, No. 24B (1994) 5833-5843. 

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